Conveyor belts



ay 1965 W. E. LANHAM 3,181,292

CONVEYOR BELTS Original Filed Dec. 21, 1956 INVENTOR. fizz/19m l'la/wm wUnited States Patent U 3,1%l,292 CUNVEYGR BELTS William E. Lanharn, 16M.lioneshoro Road SE, Atlanta 15, Ga. firiginal application Dec. 21,1956, Ser. No. 629,861. Divided and this application Nov. 13, 196i, er.No.

3 Claims. (Cl. 59-4) The present invention relates to an apparatus forfabricating a conveyor belt and is a division of application Serial No.629,861, filed December 21, 1956, now abandoned, which in turn is acontinuation-in-part of my prior application Serial No. 497 ,521, filedMarch 29, 1955 and entitled Conveyor Belt, now abandoned.

The introduction of continuous conveyor belt systems in foodmanufacturing plants constituted one of the more important advances inthe large scale factory production of food. In manufacturing plantswhere food previously had been processed in discontinuous operations orsteps, the use of conveyor belts made it possible to handle the food inone continuous operation with great savings of time and expense and muchless danger of contamination and spoilage. Moreover, the final productswere improved in quality and uniformity.

In certain food industries the benefit derived from using conveyor beltsystems was even more marked than in others. Bakeries, for example, hadlong been tied to batch production because of the special requirementsfor bread products. Bread dough appeared to demand a certain amount ofaging under exacting conditions, baking for the desired length of timeat the right temperature, and finally, after baking, the cooling of thebaked bread in a carefully controlled atmosphere to permit the loaves tobe Wrapped for later distribution to consumers.

Whereas, the cooling of the baked loaves formerly required a great dealof space in the already crowded bakery and a large number of men toservice the cooling operations, it is possible for a single conveyorsystem to free this space and the men for other uses and to give betterservice at the same time. Previously inaccessible space in the bakery,such as the space near the ceilings, can be utilized with greatefficiency by a conveyor belt. Moreover, by making the belt long enough,the bread can be cooled sufiiciently to permit wrapping after beingmoved along the belt from the ovens to a wrapping station. This makespossible the continuous operation of the ovens and the wrapping machinesand far more efficient utilization of this equipment and the bakerystaff.

Conveyor belts for this type of service are preferably of openconstruction, such as a link type belt as distinguished from a rubber orother kind of flexible sheet belt, to facilitate even cooling of thebread. Moreover, with the belt open, crumbs and the like which wouldotherwise accumulate are able to fall through the belt and out of thepath of the bread. Sanitation, so essential in the handling of foodproducts, is thus promoted. Although conveyor belts used in bakeriesmust extend for great lengths and be able to carry sizable loads, theymust be adaptable for various paths or" movement to take full advantageof the otherwise wasted space.

The conveyor belt made in accordance with the present inventioncomprises transverse metal rods held together at their ends by links soarranged in rows as to provide a continuous chain at each side of theconveyor belt. These chains may be engaged directly by sprocket wheelsthereby making possible very efficient driving of the belt, but alsothey permit the belt to be driven around relatively sharp corners and atalmost any desired upward or downward inclination. The belt isconstructed so that it needs only a minimum of lubrication andmaintenance and this, coupled with the low initial cost of the belt,results in Patented May 4, i965 substantial saving of money. Moreover,because of the relative ease of cleaning the parallel rods of the belt,even the strictest sanitary codes and practices are satisfied.

One of the objects of the present invention is to provide a method ofand apparatus for fabricating a conveyor belt of the type indicatedwhich facilitates the assembly of its parts to provide a continuous beltof any desired length. Another object is to provide a method of andapparatus for fabricating a conveyor belt of the type indicated whichwill not kink or bind during use.

Another object is to provide a method of and apparatus for fabricating aconveyor belt of the type indicated which forms the links with extremeaccuracy so that all of the links will pull evenly to provide an equaldistribution of load and wear without any lateral bending on the links.

Another object is to provide a method of fabricating the links of aconveyor belt of the type indicated which reduces scrap to a minimum.

Still another object is to provide an apparatus of the type indicatedwhich is of simple and compact construction, economical to manufactureand adapted for operation at high speed.

These and other objects will become more apparent from the followingdescription and drawings in which like characters denote like partsthroughout the several views. It is to be expressly understood, however,that the steps of the method as described herein and the apparatusillustrated in the drawings are for the purpose of describ ing andillustrating one embodiment of the invention and are not definitions ofthe limits of the invention, reference being had for this purpose to theappended claims.

in the drawings:

IGURE 1 is a front elevational view of an apparatus for carrying out thesteps of the method of the present invention and showing the parallelrows of links assembled on the rods at each end thereof;

FIGURE 2 is an enlarged side elevational view of an assembled chain ofrods and links and showing a link being assembled on a rod by aligningthe wider central portion of its slot with the end of the rod;

FIGURE 3 is a front elevational view partly in section of the rod andlink assembly illustrated in FIGURE 2 and showing how a link is slidover the end of the rod longitudinally thereof and into alignment with agroove therein during assembly;

FIGURE 4 is a sectional view taken on line 4-4 of FIGURE 1 to show oneof the sprockets for advancing the assembly of rods and links and therotating anvils for deforming successive links to lock them on the rods;and

FIGURE 5 is an enlarged sectional view taken on line 5-5 of FIGURE 4 tofurther show how the links are deformed by the anvils to lock them inthe grooves on the rods.

The conveyor belt fabricated by the method and apparatus of the presentinvention is illustrated and described in detail in my prior applicationSerial No. 479,521, referred to above, of which the instant applicationis a continuation-in-part. The conveyor belt B comprises a plurality ofspaced rods R having grooves G adjacent each end of less diameter thanthe outside diameter of the rods. A pair of flat links L .ELYC providedat each end of each rod which extend to the adjacent rods R to form acontinuous belt. Each link L has a slot S with rounded end portions S1which closely fit the peripheries of the grooves G in rods R and sidesS2 between the rounded end portions spaced at distance less than theoutside diameter of the rods R to lock the links in the grooves.

Each rod R may be formed with a single groove G adjacent each end, butin the illustrated embodiment a pair of spaced grooves G are providedadjacent each end of each rod. A pair of links L is seated in eachgroove and each link extends to an adjacent rod to provide sprocketraces X and Y between the rows of links at each side of the conveyorbelt B. The sprocket races X and Y are of a width to receive the teethof sprocket Wheels for driving the belt B. The teeth of the sprocketwheels directly engage the rods R between the spaced grooves, but thedriving force is applied to the ends of the links L at each side of theteeth to prevent the rods from bowing between their ends.

When the conveyor belt B is to be used in straight runs, all of thelinks are of equal length to hold the plurality of rods R in parallelspaced relationship. However, when the conveyor belt B is used incircular runs, the links L of each row are of a different length thanthe links L in the other rows to adapt the rods R to fan about a centralaxis, and the lengths of the links in the different rows determines theradius of the path of the belt.

The method of the present invention in one aspect comprises the steps offorming the fiat links with slots of a width to slide over the ends ofthe rods, assembling a pair of links in each slot S in each rod R whichextend to corresponding slots in adjacent rods, and deforming each linkL by compression to lock the links in the slots. The slots S in thelinks L are formed with rounded ends S1 of a diameter less than theoutside diameter of the rods R to snugly fit the outer periphery of thegrooved portions G of the rods. The sides S2 of the slots S diverge fromthe rounded ends S to provide intermediate portions of a width greaterthan the outside diameter of the rods to adapt the links to be slidlaterally over the ends of the rods into alignment with the grooves G.While the slots S may have other shapes, in the illustrated embodimentthey are made oval.

The links L may be punched from sheet stock and material may be punchedfrom the link blanks to form the slots S therein. Thus, the formed linksL are flat, comparatively thin and require a minimum space laterally ofthe conveyor belt B. Preferably, the links are made from rolled stripstock having the same width as the finished link L. The strip stock isrolled to the required thickness and with finished sides of generallyrounded contour to eliminate sharp edges. The strip is then cut inlengths corresponding to the lengths of the links L to be formed. Inorder to provide rounded ends on the links L, the sections of strip arecut on oppositely curved lines to form a link with each punching andreduce scrap to a minimum. Material then is punched from the link blanksto form the slots S. The cutting of the lengths of strip on circularlines and the punching of the slots my be performed simultaneously by asingle punching operation. Such a method of forming the links L fromroled strip stock reduces cupping or other deformation of the finishedlinks to a minimum and provides accurately dimensioned finished sidesfor engagement by the deforming anvils.

The rods R and links L are assembled by aligning.

the wider intermediate portions between the sides S2 of the slots S withthe ends of the rods and sliding the links longitudinally of the rodsinto alignment with the grooves G. Each groove G receives a pair oflinks L with each link of the pair embracing the end of one or the otherof the next adjacent rods. Thus, the links L are assembled in parallelrows at each side of the conveyor in continuous chains.

After assembling the links L on the rods R, the sides of the links arecompressed between anvils to lock the links L in the grooves G in therods R. To this end, the assembled chain of rods R and links L areadvanced and the anvils actuated in timed relation to the movement ofassembly to engage the opposite, finished parallel sides of each link atthe same place and thereby deform each link by the same amount.Preferably, the rods R and links L are continuously assembled insuccessive sections and the links deformed by rotating anvils whichengage successive links at the same intermediate point as the assemblyis advanced by sprocket wheels operating in the races X and Y. Theanvils rotate about fixed axes so as to compress the sides of the linksL toward each other and thereby compress the sides S2 of slots S intosubstantially parallel relationship with a space therebetween less thanthe outside diameter of the rods R and greater than the diameter of thegrooves G. Thus, each link L is deformed at the same place and to thesame degree so that the distance between the curved ends S1 of the slotS will be the same in all of the links. In some instances the anvils areso arranged as to deform the links L to different degrees in thedifferent rows to adapt all of the links to pull equally as for examplewhen the conveyor belt B is to be used on a circular run.

The rods R and the links L are preferably made of steel having differentcompositions with complementary bearing characteristics to reducefriction and wear to a minimum. As one example, rods of .1875 inchdiameter are composed of C1114, AISI standard, and the links of .0747inch thickness are composed of C1020, AlSI standard. After the rods Rand links L have been assembled and the links compressed to lock them onthe rods, the end portions of the rods and links are heat treated at atemperature of 1500 F. in the presence of carbonizing salt for asufficient period of time, for example 15 minutes to carbonize the linksthroughout to a brittle hardness and produce a surface hardness only onthe rods R to 8991 points on the Rockwell N scale. The two steel alloysreferred to above are particularly adapted for such heat treatment.Thus, any misalignment of the belt B which would tend to produce lateralbending of the links will cause the links to snap and break indicatingthat the belt B is not functioning properly. After the fault iscorrected, the snapped link may be replaced and deformed to lock it onthe rods R.

One form of apparatus is ilustrated in the drawings for facilitating theassembly of the links L on the rods R and deforming the links inaccordance with applicants method. The apparatus comprises a pair ofshafts 10 and 11. mounted in spaced arms 12 and 13 of a frame. Shafts 10and 11 are mounted in universal bearing blocks slidable in slots in theframe arms 12 and 13 to adapt the shafts to be adjusted toward and awayfrom each other in parallel relationship or angularly to each other.Shaft 10 mounts a pair of sprocket wheels 14 and 15 spaced a distanceequal to the spacing of the sprocket races X and Y of the conveyor beltB to be formed. The sprocket wheels 14 and 15 are adjustable laterallyon the shafts 10 and 11 to adapt them for belt B of any desired width.

Each sprocket wheel 14 and 15 has peripheral teeth 16 of a length to fitclosely between the rods R to hold them spaced and of a width to fitbetween adjacent links L. Projecting laterally from each side of theteeth 16 of each sprocket wheel 14 and 15 are cylindrical hub portionsconstituting anvils 17 which underlie one side of the links L of eachrow. Each cylindrical anvil 17 is of a diameter relative to the rootdiameter of its sprocket teeth to cause a fiat side of each link L tolie on the periphery of the cylindrical anvil tangentially as it isadvanced by the teeth 16 of the sprocket wheel.

A pair of cooperating anvil wheels 18 and 19 are mounted for lateraladjustment on and rotation with shaft 11. Each anvil wheel 18 and 19 hasspaced projecting anvils 20 with the anvils in each row angularly spaceda distance equal to the spacing between adjacent links L. Shaft 11 isdriven from any suitable source of power and shafts 10 and 11 areconnected by intermeshing gear wheels 21 and 22 for rotating theangularly spaced projecting anvils 20 in timed relation With the teeth16 on the sprocket wheels 14 and 15. The sprocket wheels 14 and 15 areso arranged with respect to the angularly spaced anvils 20 on therotating wheels 18 and 19 that the spaced projections will engage thesame intermediate portion of successive links L. The space between theperiphery of the anvils 1'7 and 29 is so dimensioned as to compress orindent the opposite parallel sides of the links L a predetermined fixeddistance inwardly toward each other. Usually, the spacing between theanvils 1'7 and 20 is such as to compress the opposite sides S2 of theslots S in the links L into parallel relationship to lock the links onthe rods R. In some instances it may be desirable to compress the linksto a greater degree and in other instances it may be desirable tocompress the links to a lesser degree depending upon the particular kindof conveyor belt to be produced. For this purpose interchangeablerotating anvil wheels 18 and 19 are provided to produce the particularcompression of the links desired.

When a chain is to be fabricated in accordance with the presentinvention, a pair of links L for each groove G are mounted on a rod R byaligning the wide central portion of the link slots S with the end ofthe rod as illustrated in FIG. 2 and sliding the links longitudinally ofthe rod until they align with a groove as illustrated in FIG. 3. Rod Rwith four pairs of links L thereon in alignment with the grooves G isthen mounted on the sprocket wheels 14 and 15 with a tooth 16 of eachwheel positioned between the pairs of links at each end of the rod. Asobserved by reference to FIG. 3, the inner adjacent links L1 and L2 ateach end are projected upwardly and the outer pair of links L3 and L4 ateach end depend or hang down from the rod R. One end of a second rod Ris then slid longitudinally through the enlarged portion S2 of the slot8 in link L3 and through a pair of additional links L1 and L2 and thenthrough the link L4. The second rod R is then slid longitudinally in areverse direction through the depending link L3 at the opposite end,through two additional links L1 and L2 and the deending link L4 until apair of links align with each of the grooves. The second rod R is thenreleased and hangs from the first rod. Rods R and links L are assembledsuccessively in the manner described above to provide a continuous chaindepending from the sprocket wheels 14 and 15. The depending chain ofrods R and links L provide the tension required to hold the pairs oflinks in the grooves G and a working end which facilitates assembly ofsuccessive rods and links.

Operation of the apparatus is then initiated by starting a motor orotherwise connecting shaft 11 to a prime mover. Rotation of shaft 11 istransmitted through gears 21 and 22 to rotate shaft and thereby rotatethe opposed sprocket wheels 14 and 15 and the anvil wheels 18 and 19 inopposite directions. The teeth 16 of the rotating sprocket wheels 14 and15 advance the assembly and move the rows of links L between therotating anvils 1'7 projecting laterally from each side of the teeth onthe sprocket wheels and the cooperating anvils Zll on the anvil wheels18 and 19. As illustrated in FIG. 4, one of the anvil projections on therotatable anvil wheel 18 will engage one side of a link L at a pointintermediate its ends at the same time that anvil 17 engages acorresponding point at the opposite side of the link to compress anddeform the sides 17 inwardly toward each other to lock the links L onthe rods R.

As the sprocket wheels 14 and 15 advance the assembly, the series ofprojecting anvils 2%) on the rotating anvil wheels 18 and 19 willcompress successive links L in each row of links equal amounts in acontrolled manner to form links of the same length between their roundedends S. As the rotating anvils 17 and 20 successively compress anddeform the plurality of links L as they are advanced by the sprocketteeth 16, an operator assembles additional links L and rods R at thelower end of the depending chain. The shafts 10 and 11 may becontinuously rotated or may be rotated under the control of theoperator.

When the conveyor belt is to be used on horizontal circular runs, thelinks L in successive rows are made progressively shorter so that therods R may fan outwardly about a fixed axis. The rods R and links L areassembled in the same manner as previously explained, but suitablesprocket wheels id and 15 and anvil wheels 18 and 19 to accommodate theshorter links L are substituted. Shafts it? and 11 also are adjustedangularly to accomodate the lesser wheel circumference. In someinstances, the same links L may be used in the different rows at thesame side of the belt B and the links in the different rows deformed bythe anvils 1'7 and Ell to a greater and lesser degree to produce therequired difference in length. Thus, the anvils 17 and 2% provide anaccurate control of the length of the links L.

While the method and one embodiment of apparatus for carrying out thesteps of the method are herein described and illustrated, it will beunderstood that changes may be made in the steps of the method and inthe form of the apparatus without departing from the spirit or scope ofthe invention. Therefore, without limitation in this respect, theinvention is defined by the following claims:

I claim:

1. Apparatus for fabricating conveyor belts by deforming links assembledon and extending between grooves in the ends of adjacent rods comprisinga rotatable shaft, sprocket wheels mounted on the shaft in spacedrelation thereon and having radially projecting teeth of a length toclosely fit between adjacent rods at one side of the links to positionadjacent rods at the ends of the links at each end thereof, a hubprojecting laterally from at least one side of each sprocket wheel tounderlie the links and constituting anvils at one side of the links, asecond rotatable shaft mounted in parallel relation to the firstmentioned shaft, anvil wheels mounted in spaced relation on said secondshaft with each anvil wheel cooperating with a corresponding sprocketwheel, each of said anvil wheels having spaced radially projecting anvilteeth in alignment with and overlying the hub projecting laterally fromits corresponding sprocket wheel, the end of each anvil tooth beingspaced from the periphery of its corresponding hub a distance to engageand deform a link therebetween and produce a parallel relation of theinner edges of the link to lock the link in the grooves in the rods,said anvil teeth on each anvil wheel being of an arcuate length toengage successive links centrally thereof and spaced from each other todisengage the end portions of the links surrounding a rod, gearsconnecting said shafts to deform successive links as they pass bewteenthe hub and anvil teeth on the sprocket and anvil wheels, and means fordriving at least one of said shafts.

2. Apparatus in accordance with claim 1 in which each sprocket wheel hashubs projecting from the opposite sides thereof, and each anvil wheelhas spaced rows of teeth located at opposite sides of the radiallyprojecting teeth on its corresponding sprocket wheel and aligned withand overlying the hubs on the sprocket wheel whereby to deform and lockpairs of spaced links at each end of the rods.

3. Apparatus in accordance with claim 1 in which the hubs and teeth oneach sprocket wheel and cooperating anvil wheel, respectively, extendaxially of the shafts on which they are mounted a distance to overlietwo links arranged in side by side relationship.

References Cited by the Examiner UNITED STATES PATENTS 804,799 11/05Edison 15 3-28 1,748,978 3/30 Feeney 15328 1,810,724 6/ 31 Parker 59-61,833,616 11/31 Nelson et al 153-28 1,899,948 3/33 Fahrenwald 59-5MICHAEL V. BRINDISI, Primary Examiner.

HUNTER C. BOURNE, In, Examiner.

1. APPARATUS FOR FABRICATING CONVEYOR BELTS BY DEFORMING LINKS ASSEMBLEDON AND EXTENDING BETWEEN GROOVES IN THE ENDS OF ADJACENT RODS COMPRISINGA ROTATABLE SHAFT, SPROCKET WHEELS MOUNTED ON THE SHAFT IN SPACEDRELATION THEREON AND HAVING RADIALLY PROJECTING TEETH OF A LENGTH TOCLOSELY FIT BETWEEN ADJACENTS RODS AT ONE SIDE OF THE LINKS TO POSITIONADJACENT RODS AT THE END OF THE LINKS AT EACH END THEREOF, A HUBPROJECTING LATERALLY FROM AT LEAST ONE SIDE OF EACH SPROCKET WHEEL TOUNDERLIE THE LINKS AND CONSTITUTING ANVILS AT ONE SIDE OF THE LINKS, ASECOND ROTATABLE SHAFT MOUNTED IN PARALLEL RELATION TO THE FIRSTMENTIONED SHAFT, ANVIL WHEELS MOUNTED IN SPACED RELATION ON SAID SECONDSHAFT WITH EACH ANVIL WHEEL COOPERATING WITH A CORRESPONDING SPROCKETWHEEL, EACH OF SAID ANVIL WHEELS HAVING SPACED RADIALLY PROJECTING ANVILTEETH IN ALIGNMENT WITH AND OVERLYING THE HUB PROJECTING LATERALLY FROMITS CORRESPONDING SPROCKET WHEEL, THE END OF EACH